Serious pneumatic air leakage may occur if a tire is flat during driving. Among technical solutions to prevent such an accident as described above, a run-flat tire in a sidewall reinforcement manner, a sealant tire with instant hole sealing performance wherein a flowable material is provided inside the tire, or the like, have been disclosed.
For the sidewall reinforcement manner, introducing an insert material into the sidewall can allow driving even though the tire pressure is empty. However, it has a defect that the weight of tire is necessarily increased. In addition, since the sidewall part has higher stiffness, running stability may be reduced. Furthermore, in case where the tire is damaged by a sharp object such as a nail, a high pressure is applied to the tire during high-speed driving and, at the same time, the tire changes into a more elastic state and the foregoing object may easily become detached from the tire. As a result, the tire pressure is rapidly reduced causing the driver difficulties in operating a vehicle or throwing the vehicle off balance, hence seriously influencing the safety of the driver.
Meanwhile, a sealant tire technique is to coat an inner side of the tire with a sealant material so that, when a hole is opened in the tire, the sealant material outflows from the hole portion by a tire pressure and exerts instant self-sealing effects, simultaneously, thereby filling the hole portion of the tire and maintaining a desired tire pressure. However, since the sealant material used in the sealant technique generally has the same color as that of the tire, the consumer may not recognize an opening in the tire or forget it's occurrence and therefore neglect replacing the flat tire, hence often causing a negative influence upon driver safety.
Meanwhile, among prior arts related to the present invention, Korean Patent Laid-Open Publication No. 2004-0044476 discloses a sealant layer provided in an area corresponding to at least a tread part in a tire. Such a sealant layer may include an adhesive sealant prepared by heating a rubber composition which includes 0.2 to 20 wt. parts of peroxide admixed to 100 wt. parts of a rubber component containing at least 50 wt. % of polyisobutylene. There is a disclosure that describes an air tire fabricated by adding, as an adhesive contained in the sealant layer, 5 to 50 wt. parts of liquid ethylene, α-olefin copolymer, liquid polybutadiene or liquid polyisoprene, a method for fabrication of the foregoing tire, and a rubber composition for sealant.
Further, Korean Patent Laid-Open Publication No. 2010-0041368 discloses a sealant composition for an automobile tire, which includes 20 to 60 wt. parts of a sealing agent, 20 to 40 wt. parts of an anti-freezing agent, 0.5 to 8 wt. parts of an adhesive agent, 10 to 35 wt. parts of solid content and 2 to 10 wt. parts of deionized water, thus exhibiting excellent sealing effects when applied to a flat tire.
However, the present invention involves different technical features, compared to the foregoing prior arts, therefore, has inventive configurations clearly distinguished from those of the foregoing prior arts.